The Agilent 1260 Infinity II Flexible Pump

Significance of the Topic

The Agilent 1260 Infinity II Flexible Pump addresses the growing need in analytical chemistry for a versatile low-pressure gradient pump capable of delivering exceptional mixing accuracy, retention time precision, and rapid gradient performance across a wide range of HPLC applications.

Objectives and Study Overview

This technical overview benchmarks the 1260 Infinity II Flexible Pump against the established 1260 Infinity II Binary Pump. The comparison covers step gradients, shallow slopes, low and high organic percentage runs, and accelerated high-flow methods to assess composition accuracy, delay volume, mixing noise, flow accuracy, and retention time reproducibility.

Instrumentation

• Agilent 1260 Infinity II Flexible Pump (G7104C)
• Agilent 1260 Infinity II Binary Pump (G7112B)
• Agilent 1260 Infinity II Multisampler with cooler (G7167A, option #100)
• Agilent 1260 Infinity II Diode Array Detector WR (G7115A)
• Agilent 1260 Infinity II MCT (G7116A)

Methodology and Instrumentation

A series of gradient experiments was performed using various model compounds: acetone tracer steps, polyphenolic mix under shallow gradients, sulfa drugs at low organic content, Sudan Red dyes at high organic levels, and a fast RRLC sample at elevated flow. Chromatographic conditions (solvents, column types, temperatures, detectors) were standardized. Composition accuracy and flow were measured with step gradients and a flow accuracy meter; retention time precision was derived from multiple consecutive injections.

Key Findings and Discussion

The 1260 Infinity II Flexible Pump delivered composition accuracy within ±0.4% (spec ±0.4%), comparable to the Binary Pump’s ±0.35% specification. System delay volumes measured 310 µL (flexible pump alone), 460 µL (with 380 µL Jet Weaver mixer), and 610 µL (binary pump). Mixing noise was lowest with the Jet Weaver mixer (<0.015% at 95% A). Real-time flow accuracy remained within ±0.3% for all pumps. Retention time RSDs were below 0.15% across shallow gradients, low/high organic runs, and fast 2 mL/min and 2.6 mL/min experiments, demonstrating equivalent or superior performance of the Flexible Pump versus the Binary Pump even under demanding conditions.

Benefits and Practical Applications

The 1260 Infinity II Flexible Pump offers:

• Seamless switching between conventional and high-throughput columns
• Low delay volume for rapid gradients
• Integrated mixing options to minimize noise
• High precision in composition and flow for QA/QC and research applications

Future Trends and Applications

Emerging directions include further miniaturization for micro- and nano-LC, integration with mass spectrometry and sample preparation modules, advanced digital control for predictive maintenance, and environmentally sustainable solvent management. Enhanced software analytics will drive automated method development and real-time data interpretation.

Conclusion

The Agilent 1260 Infinity II Flexible Pump matches or exceeds the performance of a traditional binary gradient pump across multiple challenging scenarios. Its flexibility, low delay volume, and robust mixing capabilities make it an ideal choice for modern HPLC workflows demanding precision, speed, and versatility.